In oil field operations, reciprocating pumps are often used for various purposes. Some reciprocating pumps, generally known as “service pumps,” are typically used for operations such as cementing, acidizing, or fracing a well. Typically, these service pumps run for relatively short periods of time, but they operate on a frequent basis. Often they are mounted to a truck or a skid for transport to various well sites. A pump might operate several times a week. In many applications, several pumps are connected in parallel to a single flow line.
High pressure pumps are widely used in the petroleum industry for a variety of field operations relating to oil and gas wells. Such pumps deliver a fluid or slurry, which may carry solid particles (e.g., a sand proppant), at pressures up to 20,000 psi. A common type is a positive displacement pump having one or more plungers reciprocally movable in a corresponding pump chamber. Each chamber has an intake port for receiving fluid, a discharge port for exhaust, and a one-way flow valve in each port for preventing reverse flow. These valves require frequent maintenance.
With the many different ports and chambers in a high pressure pump, it is advantageous to ensure that threaded assemblies are securely threaded into the corresponding bores of the pump assembly. Unfortunately, many of these threaded assemblies are prone to inadvertently loosen. The pump experiences substantial vibration during operation at high power settings such that the threaded assemblies may overcome their initially applied torque and begin to “back out”, or rotate in a loosening direction. With respect to many of the threaded assemblies, should the assemblies continue to loosen, the closure, and in some instances, a quantity of high pressure fluid may be ejected from the pump housing and potentially cause damage or injury. Consequently, safety regulations demand that operators respond to any loosening of threaded assemblies by stopping the pump. That degrades efficiency and can necessitate the expense of a back-up pump for continuing a pumping operation while the primary pump is shut down.